Coke oven gas (COG) is a byproduct gas generated during a coke dry distillation process carried out in iron and steel making industry. COG is mostly used as a fuel in steel plants through a purification process, and amplification of COG has emerged as an important issue, as the amount of COG used in the iron and steel making industry has recently increased.
Meanwhile, the mass production of hydrogen has emerged as an important issue due to the recent carbon dioxide problem, in which COG has received attention as a potential fuel from which hydrogen can be mass-produced.
However, it may be difficult to recover energy from high-temperature crude COG through a heat exchanger, due to an existence of tar or hydrogen sulfide (H2S) included in the crude COG. In order to address such limitations, research on the decomposition of tar in high-temperature crude COG by using a catalyst or on the amplification of a combustible gas component by introducing oxygen and allowing partial oxidation to occur at a high temperature of about 1200° C. has recently been conducted in Japan. However, there may be issues of technical and economical limitations caused by catalyst regeneration and high oxygen consumption in such methods.
Research on obtaining carbon monoxide and hydrogen through reactions between carbon and carbon dioxide or water has received attention as a major potential method of coal gasification. However, high-temperature heat energy should be required for gasification and a large amount of oxygen should be used to implement this requirement.